JP2009043238A - Storage area management method and information processing apparatus - Google Patents

Abstract

In a storage device, it is possible to prevent the risk of data loss due to area degeneration when the number of erased erase blocks decreases, and a significant decrease in writing speed.
In a new page securing process, it is determined whether the length of a used page list is longer than an arbitrary n page. If it is longer, one page is secured from the used page list. If it is shorter, a capacity shortage error is returned and the process is terminated. For deleting a file in the erased page list, it is determined whether a page to be processed becomes empty due to file deletion. When it becomes empty, the content of the last page of the used page is copied to the page, erase data is written to the last page, and the erase block included in the last page is to be erased. Subsequently, the last page is deleted from the in-use page list, added to the erased page list, and the process ends.
[Selection] Figure 1

Description

  The present invention relates to a data management technique related to a storage apparatus, and more particularly to data management using a file system area or a database area, and more particularly to management of a file system area or a database area of a storage apparatus.

  For example, file system technology and database technology are known as methods for efficiently managing data on a storage device exemplified by a hard disk drive.

  The file system technology is a technology for mainly handling a large number of files having a size of several KB or more. A management structure called a file system area is created on the storage, and this file system area is operated mainly through a file system processing unit that operates as a part of the operating system. A system that manages data by a file system area and a file system processing unit is called a file system.

  The database technology is a technology for mainly handling a large number of records having a size of about several tens of B. A management structure called a database area is created on the storage, and this database area is operated via a database management program that operates mainly on the operating system. A system that manages data using a database area and a database management program is called a database management system.

  Furthermore, it is often possible to create a hierarchy such as creating a database area on the file system area or conversely creating a file system area on the database area.

  These file system technologies and database technologies have been developed mainly with the intention of operating them on hard disk drives. One characteristic of a hard disk drive is that the number of rewritable times of a magnetic material that is a storage element is virtually unlimited.

  For this reason, in file system technology and database technology, metadata, which is management information for the entire area, is often fixed at a location such as the beginning or end of the area and repeatedly overwritten.

  On the other hand, in recent years, replacement of hard disk drives by silicon storage represented by nonvolatile semiconductor memories such as flash memories has been advanced.

  Here, the nonvolatile semiconductor memory has a memory cell, which is the minimum unit of the memory element, that has a rewrite count of about 105 times, which is smaller than that of a hard disk drive. It is necessary to perform management such as used wear leveling 2001 (equalizing the number of rewrites) and reassignment 2002 of defective erase blocks.

  On the other hand, since data is generally protected using parity, once written data does not become unreadable. Further, in order to hold the parity and wear leveling logical addresses, the parity and wear leveling logical addresses are stored in the memory cells in addition to the actual data.

  In nonvolatile semiconductor memory, the number of times that memory cells can be rewritten is less than that of hard disk drives, and it is very difficult to handle because it requires usage based on the presence and occurrence of defective erase blocks. The use of such a memory card has been the mainstream in recent years.

  Here, the erase block refers to the minimum unit of erasure in the nonvolatile semiconductor memory. In the memory cell of the nonvolatile semiconductor memory, the write operation for each cell can be performed only in the direction of “1” → “0”, and the change in the direction of “0” → “1” is performed by an erase operation in units of erase blocks. It can only be done.

  As the capacity of the non-volatile semiconductor memory is increased, the size of the erase block is also increased, and the current NAND flash memory has a size of 128 KB or more.

  A memory card generally has a configuration in which a nonvolatile semiconductor memory and a memory control unit are packaged. The lifetime of non-volatile semiconductor memory (about 105 times can not be achieved without adhering to the recommended parity bit length of the memory vendor and the number of spare erase blocks, but these parameters vary between memory vendors and within the same vendor and between parts generations. .

  Furthermore, since the model cycle of the nonvolatile semiconductor memory is one year but the CPU (Central Processing Unit) / chipset is about two years, the nonvolatile semiconductor memory with the latest bit unit price is low throughout the model cycle of the final product. Is simple and effective to use a memory card.

  In general, I / O interfaces of general-purpose storage such as ROM (Read Only Memory) and USB (Universal Serial Bus) mass storage are emulated via a memory control unit, and connectivity with existing CPUs and chipsets Is increasing.

  Further, the spare erase block refers to an erase block used when reassigning a defective erase block. In general, it is necessary to design the spare erase block so as to be used only for reassignment of a defective erase block, and it should not be used as a replacement erase block at the time of update.

  There are two physical states of the erase block, ie, whether data is written or not. Logically, as shown in FIG. 12, there are 3 erased → in use → used (→ erased). Managed in one state.

  Here, the erased erase block (state 3001) shown in FIG. 12 indicates an erase block in which all data is initialized to '1'. In a memory card, erased erase blocks are generally managed in a list structure, and are used for securing a new segment or updating existing data.

  However, data other than “1”, such as the number of rewrites, may be written in the metadata portion. Furthermore, the data in the logical address to which the used erase block is not assigned is assumed to be “0”, and the used erase block in which all the data of the included segment happens to be “0” is to be erased. it can.

  The in-use erase block (state 3002) in FIG. 12 indicates an erase block in which data is written and assigned to a logical address. When data on the memory card is overwritten and updated from the outside, an operation is actually performed in which data is written to another erased erase block and an in-use erase block is added to a used erase block sequence.

  The used erase block (state 3003) refers to an erase block in which data generated by an overwrite update operation on the used erase block is written but not assigned to any logical address.

  It is erased at idle time by the memory controller and added to the list of erased erase blocks. In addition, an erase block in which all of the included segment data is exceptionally “0” can be treated as a used erase block even if it is assigned to a logical address (3004). It can also be handled.

  However, in a memory card, it may be encapsulated in a package and state change may not be controlled from an external general-purpose storage I / O interface. Depending on the memory card product, the general-purpose I / O interface may be extended to have a special erasure command that indicates that the erase block can be erased.

  As described above, when the memory card is used, the miscellaneous management inherent to the nonvolatile semiconductor memory is concealed, and a storage operation using a general general-purpose storage interface becomes possible.

  However, the present inventors have found that the storage device data management technology using the nonvolatile semiconductor memory as described above has the following problems.

  In other words, the number of rewritable times of memory cells cannot be completely concealed, and even when using a storage medium such as a memory card, there is a problem if the file system technology and database technology developed for hard disks are applied as they are There is.

  When the number of erased erase blocks in the memory card is reduced, there is a problem that the risk of data loss due to the area degeneration increases or the writing speed is greatly reduced.

  Here, area degeneration refers to a phenomenon in which the physical length of a storage area appears to be small when a defective erase block occurs in a state where a memory card is used and there are no spare erase blocks.

  Here, the decrease in the writing speed occurs when data is updated or inserted in an environment where a memory card is used, with no erased erase blocks. In this case, it is necessary to first erase the used erase block to create an erased erase block, and to update or insert data into the erased erase block, so that the speed is reduced.

  An object of the present invention is to provide a technology capable of preventing data loss or a significant decrease in writing speed due to area degeneration even in a storage device such as a memory card even if the number of erased erase blocks decreases. is there.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  For example, there is a storage area management method for managing a storage apparatus including a storage area group composed of a plurality of storage areas capable of storing data used by an application. That is, when an application no longer uses data stored in a certain storage area, the data from the end storage area where the data used by the application is stored is stored in the other storage area group. Move to the storage area and erase the data from the source storage area. The source storage area is set as an erased storage area. Then, when allocating a storage area to an application, it is determined whether or not the number of erased storage areas is larger than a predetermined number of storage areas. If the determination result is large, a predetermined storage area is determined from the end of the erased storage area. A storage area is allocated to an application from erased storage areas before the number.

  The present invention also relates to a storage area management method for managing data in a storage apparatus by a logical data management layer having an exclusive control manager, and obtains write exclusive control rights for the entire data management layer from the exclusive control manager. A step of acquiring, a step of acquiring a segment management structure of the data management layer from which the exclusive control right has been acquired, and acquiring all storage areas managed by the acquired segment management structure and acquiring from among them And when determining whether there is a storage area that cannot be acquired based on the listed list, and when it is determined that there is a storage area that cannot be acquired, the list is displayed. Reconfiguring the segment management structure based on the data management layer upon initial access to the data management layer. When mounting the layer, and changes the storage capacity in the data management layer when the storage capacity in the storage apparatus has been changed.

  Furthermore, the present invention provides a storage area management method for managing data in a storage apparatus by a logical data management layer having an exclusive control manager, wherein the exclusive control right of the entire storage area is written from the exclusive control manager. A step of acquiring the segment management structure of the storage area for which the exclusive control right has been acquired, and acquiring all the storage areas managed by the acquired segment management structure, A step of listing, a step of determining whether there is a storage area that cannot be obtained based on the listed list, and a step based on the listed list when it is determined that there is a segment that cannot be obtained. Reconfiguring the segment management structure and storage available for the reconfigured segment management structure If the area is not included, the step of acquiring the write exclusive control right of the entire data management layer from the exclusive control manager, the step of acquiring the segment management structure of the data management layer that acquired the exclusive control right, and the acquired segment management A step of removing a segment from the structure that has acquired exclusive write control of the entire storage area from the exclusive control manager, and when detecting that the capacity of the storage device has changed, in the data management layer It handles changes in storage capacity.

  Moreover, the outline | summary of the other invention of this application is shown briefly.

  An arbitrary natural number n defined in advance is used to manage the last n erase blocks in the virtual storage area in a storage device such as a memory card to be erased.

  However, depending on the type of storage device, there may be no interface for operating the erase block from the outside. In such a case, the last m storage areas of the file system area and database area are erased using the natural number m defined so that the m storage areas have the same capacity as n erase blocks. And informs the memory card that the corresponding erase block can be erased.

  Here, when a natural number p is given in advance, n = p, and otherwise, a natural number q defined by a file system processing unit, a database management program, OS (Operating System) or other middleware is used. N = q.

  According to one aspect of the present invention, it can be ensured that a predetermined number of storage areas have been erased from the end in the storage area group. In addition, reliability can be improved without degrading storage device performance.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

(Embodiment 1)
FIG. 9 shows the configuration of an apparatus 5020 that implements the information processing system in this embodiment. The apparatus is a computer including a CPU 5001, a main storage device 5002 such as a RAM (Random Access Memory), and a memory card 5003 as a secondary storage device. The memory card 5003 is connected via the storage interface 5100.
The CPU 5001 manages the data on the memory card 5003 by executing the operating system 5004, the file system processing program 5005, and the AP execution unit 5019 on the main storage device 5002.
The AP execution unit 5019 executes the function of the information processing system in the present embodiment, and delegates the processing to the file system processing program 5005 when access to the memory card 5003 becomes necessary at that time.
The file system processing program 5005 includes a first file deletion module 5006, a new segment allocation module 5007, a used segment deletion module 5008, a file system metadata reorganization module 5009 module 5009, a segment metadata reorganization module 5010, and in use. It has a segment list 5011 and an erased segment list 5012.
The first file deletion module 5006 performs file deletion processing according to the flowchart shown in FIG.
The new segment securing module 5007 performs a new segment securing process according to the flowchart shown in FIG.
File system metadata reorganization module 5009 The module 5009 performs file system metadata reorganization processing according to the flowchart shown in FIG.
The segment metadata reorganization module 5010 performs segment metadata reorganization processing according to the flowchart shown in FIG.
The in-use segment list 5011 and the erased segment list 5012 manage the numbers of in-use and erased segments, respectively.
The memory card 5003 includes a nonvolatile semiconductor memory 5013 and a memory control unit 5014. The nonvolatile semiconductor memory 5013 and the memory control unit 5014 are connected.
The inside of the nonvolatile semiconductor memory 5013 is divided into n erase blocks 5015. An erase block 5014 is an erasable management unit of the nonvolatile semiconductor memory 5013, and is identified by a unique number.
The memory control unit 5014 manages state transitions in the nonvolatile semiconductor memory shown in FIG. 12 by managing the used erase block list 5016, the used erase block list 5017, and the erased erase block list 5018.
The in-use erase block list 5016, the used erase block list 5017, and the erased erase block list 5018 each manage the number of the erase block 5014 in a list. Note that the memory card 5003 may be outside or inside the device 5020.
1 is a block diagram of an information processing system according to Embodiment 1 of the present invention, FIG. 2 is a flowchart showing an example of a new segment securing process by the information processing system of FIG. 1, and FIG. 3 is an information processing system of FIG. 5 is a flowchart showing an example of a file deletion process by.

  In the first embodiment, the information processing system includes a computer system such as a personal computer, for example. As shown in FIG. 1, the information processing system is provided with a main board 4001.

  The main board 4001 is a board on which basic electronic components such as a memory and a CPU and an expansion slot are mounted. For example, a memory card 4005 typified by an SD (Secure Digital) card is connected to the main board 4001 via a standard general-purpose storage interface 4004 such as ATA or USB mass storage. .

  Here, a partition on the storage is managed by a file system or a database management system. In general, a file system or a database management system manages partitions on a storage in units called segments. A segment has a structure in which a plurality of pages, which are the smallest access units on the storage, are arranged.

  In general, a file system and a database manage a used segment and a used segment, respectively, but this system is characterized by managing an erased segment instead of a used segment.

  In-use segments are segments that are used to store significant data. Erased segments are segments that are not used to store significant data, and have been erased by writing erase commands or erasure data. It is. A used segment is a segment that is not used for storing significant data but is not included in the erased segment because no erase command or data for erasure is written.

  These used segments, used segments, erased segments, and other storage area management information are collectively stored in a special location in a storage area called a segment management structure or super block. The segment management structure is often placed near the beginning of the storage area.

  A file system processing unit that operates on the main board 4001 manages an in-use segment list 4002 that is a list of in-use segments and an erased segment list 4003 that includes an erased segment list.

  A memory card 4005 serving as a storage device includes a memory control unit 4006 that controls the memory card 4005 and a nonvolatile semiconductor memory 4007 exemplified by a flash memory. The memory card 4005 is not particularly limited as long as it can be accessed by a standard storage I / O interface such as ATA (Advanced Technology Attachment) or USB mass storage.

  Further, the memory control unit 4006 manages the in-use erase block list 4008, the used erase block list 4009, and the erased erase block list 4010, respectively. That is, the memory control unit 4006 manages the usage status of the storage area of the nonvolatile semiconductor memory.

  Here, the erase block is a minimum unit of erasure in the nonvolatile semiconductor memory 4007. The used erase block is an erase block in which data generated by an overwrite update operation on the used erase block is written but not assigned to any logical address.

  Further, the erased erase block is an erase block in which data is all initialized to “1”, and the in-use erase block is an erase block in which data is written and assigned to a logical address.

  On the storage area provided by the memory card 4005, a file system area 4011 for mainly managing files having a size of several KB or more is configured. The file system area 4011 performs data management by the file system processing unit described above. Further, the memory control unit 4006 has a function of regarding a currently used erase block whose data is “0” as an erasure target.

  Next, a segment management technique by the information processing system in the first embodiment will be described.

  First, a new segment securing process when a new segment is required when the AP execution unit 5019 delegates file creation or update to the file system processing program 5005 will be described with reference to the flowchart of FIG.

When the new segment securing process is started, it is determined whether or not the length of the erased segment list 4003 is longer than an arbitrarily set n (natural number) segment (step S5001). One segment is secured from the completed segment list 4003 (step S5002), and the process ends. On the other hand, if it is not long in the process of step S5001, an insufficient capacity error is returned (step S5003), and the process ends.
Next, file deletion processing when the AP execution unit 5019 delegates file deletion to the file system processing program 5005 will be described with reference to the flowchart of FIG.

  When the file deletion process is started, it is determined whether or not the segment including the file to be processed becomes empty due to the file deletion (step S6001). If the segment is not empty, the file is deleted from the segment ( Step S6002), the process is terminated.

  As a file deletion method, for example, a method of writing “0” to a segment actually used by the file, or a segment used by the file by operating only the management information of the segment is not assigned data. There are things to consider.

  On the other hand, when the segment becomes empty in the process of step S6001, the contents of the last segment a among the used segments are copied to the segment (step S6003), and all the erase data is stored in the segment a. “0” is written (step S6004).

  By this operation, the erase block included in the segment a becomes an erasure target of the memory control unit 4006. Subsequently, the segment a is deleted from the in-use segment list 4002 (step S6005), the segment a is added to the erased segment list 4003 (step S6006), and the process ends.

  If the memory card 4006 being used has a block erase command, the erase command is issued to the location corresponding to segment a in the process of step S6004.

  When the present embodiment is implemented, if the size of the segment is set to be equal to or larger than the size of the erase block, the operation of writing all “0” in the empty segment (step S6004) is surely performed. The erase block included in the can be erased.

  As a result, according to the first embodiment, even if the area degeneration accompanying the generation of a defective erase block at the time of writing to the nonvolatile semiconductor memory 4007 occurs, there is an effect of preventing data loss if the defect is within n erase blocks. can get.

  In addition, since erased erase blocks are prepared at the time of writing, it is possible to prevent a decrease in writing performance.

  Although the management in units of segments has been described here, the page may be used as the management unit when the number of pages is small in a small storage or the like.

  In this case, a page management structure is placed at a special location in the storage area, and used pages, used pages, and erased pages are managed.

  Furthermore, it is conceivable to introduce a higher management unit in which a plurality of segments are combined in the future, or a higher management unit, but the present invention is also applicable to all these management units.

(Embodiment 2)
FIG. 10 shows the difference from FIG. 9 in the configuration of the apparatus for realizing the information processing system in the present embodiment. The apparatus includes a CPU 5001, a main storage device 5002 such as a RAM, and a memory card 5003 as a secondary storage device.
The file system processing program 5005 in this embodiment has a used segment list 6013. The used segment list 6013 manages the numbers of used segments in a list.
The second file deletion module 6006 performs file deletion processing according to the flowchart shown in FIG. 5. Further, the used segment deletion module 6008 performs used segment deletion processing according to the flowchart shown in FIG.
4 is a block diagram showing a configuration example of an information processing system according to the second embodiment of the present invention, FIG. 5 is a flowchart showing an example of file deletion processing by the information processing system of FIG. 4, and FIG. 6 is the information of FIG. It is a flowchart which shows the example of a deletion process of the used segment by a processing system.

  In the second embodiment, as shown in FIG. 4, the information processing system has the same configuration as that of the first embodiment except that a file system processing unit operating on the main board 4001 is in use. A segment list 4012, a used segment list 4013, and an erased segment list 4014 are managed.

  In this case, the information processing system has a management structure including pages and segments on the storage of the memory card 4005.

  Here, the in-use segment is used for storing significant data, and the erased segment is not used for storing significant data, and is erased by writing an erasing command or erasing data. It has been done. A used page is a segment that is not used for storing significant data and is not included in an erased page.

  A file system area 4011 is configured on the storage area of the memory card 4005 as in the first embodiment. Further, the memory control unit 4008 has a function of considering an in-use erase block whose data is “0” as an erasure target.

  Also in the second embodiment, when a new segment becomes necessary when creating or updating a file, the processing shown in FIG. 2 of the first embodiment is executed.

  On the other hand, the process for deleting a file is different from the first embodiment, and the process proceeds according to the flowcharts shown in FIGS.

  First, in FIG. 5, when the file deletion process is started, it is determined whether or not the segment including the file to be processed becomes empty due to the file deletion (step S8001). The file is deleted (step S8002), and the process ends.

  If the segment becomes empty in the process of step S8001, the segment is deleted from the in-use segment list 4012 (step S8003), and the segment is added to the erased segment list 4014 (step S8004). The process ends.

  Subsequently, the segment added to the used segment list 4013 by the processing of FIG. 5 is appropriately deleted according to the flowchart shown in FIG.

  In FIG. 6, when the used segment erasing process is started, one segment is extracted from the used segment list 4013 (step S9001), and the content of the last segment a among the used segments is copied to the segment. (Step S9002), all 0s are written in the segment a (step S9003), the segment a is added to the erased segment list 4014 (step S9004), and the process is terminated.

  As the start timing of the used segment erasure process shown in FIG. 6, for example, when there is no processing for a certain period of time, or when the used segment list 4014 exceeds a certain length, the new segment securing process has insufficient capacity. There is a case where an error (the process of FIG. 2, step S5003) occurs.

  As a result, even in the second embodiment, even if the area degeneration accompanying the generation of a defective erase block at the time of writing to the nonvolatile semiconductor memory 4007 occurs, the effect of preventing data loss is obtained if the defect is within n erase blocks. It is done.

  Further, since erased erase blocks are prepared at the time of writing, it is possible to prevent a decrease in writing performance.

  Furthermore, the overall processing response time can be improved by strictly managing the used segment and the erased segment.

  Further, even if a used page and an erased page are managed separately in a system that does not have a management unit corresponding to a segment, the same effect can be obtained.

(Embodiment 3)
FIG. 7 is a flowchart showing an example of metadata reconstruction processing of the file system area by the information processing system according to the third embodiment of the present invention, and FIG. 8 is segment metadata by the information processing system according to the third embodiment of the present invention. It is a flowchart which shows the example of a reconstruction process.

  In the third embodiment, in the configuration information processing system similar to the first and second embodiments, an example of a countermeasure technique when the storage area is degenerated due to the erase block failure of the nonvolatile semiconductor memory 4007 will be described.

  Deterioration of the storage area length may be detected when a file system is mounted or written. In this case, the metadata reconstruction process for the file system area shown in FIG. 7 is performed, and then the segment metadata reconstruction process shown in FIG. 8 is performed to cope with the degeneration.

  First, when the metadata reconfiguration process of the file system area is started, an exclusive control manager (not shown) in the file system processing unit acquires the write exclusive right of the entire file system area (step S10001), and the current meta Data is acquired (step S10002).

  Subsequently, each segment linked from the metadata is acquired, a list A of those that can be acquired is created (step S10003), and it is determined whether there is a segment that cannot be acquired (step S10004).

  If all segments can be acquired in the process of step S10003, it can be determined that the current state of the file system area and the metadata of the file system area are consistent. Is released (step S10005), and the process ends.

  On the other hand, if there is a segment that cannot be acquired in the process of step S10003, the metadata is reconstructed from the list A (step S10006).

  Subsequently, in the segment metadata reconstruction process shown in FIG. 8, since the segment affected by the region degeneration is limited to the tail, first, the write exclusive right of the entire tail segment is acquired (step S11001). Metadata is acquired (step S11002).

  After that, each page linked from the metadata is acquired and a list B of those that can be acquired is created (step S11003), and it is determined whether there is a page that cannot be acquired (step S11004).

  If all pages can be acquired, it can be determined that the current state of the segment and the metadata of the segment are consistent, so the write exclusive right for the entire last segment is released (step S11005). Finish the process.

  On the other hand, if there is a page that cannot be acquired in the process of step S11004, the metadata is reconstructed from the list B (step S11006), and it is determined whether or not the page of the last segment is completely destroyed (step S11006). Step S11007).

  If not completely destroyed, the metadata is overwritten (step S11008). If the processing in step S11007 has been completely destroyed, the write exclusive right for the entire last segment is released (step S11009), and the write exclusive right for the entire file system area is acquired (step S11010).

  Then, the tail segment is deleted from the metadata of the file system area (step S11011), the write exclusive right of the entire file system area is released (step S11012), and the new tail segment is checked for defects. The processing returns to step S11001.

  In this example, the file system is hierarchized with pages, segments, and the entire file system in ascending order of granularity. However, the same procedure is repeatedly applied to deeper file systems and database management systems as appropriate. This can be dealt with.

  As a result, even according to the third embodiment, even if the area degeneration accompanying the generation of a defective erase block at the time of writing to the nonvolatile semiconductor memory 4007 occurs, the effect of preventing data loss can be obtained if the defect is within n erase blocks. It is done.

  In addition, since erased erase blocks are prepared at the time of writing, it is possible to prevent a decrease in writing performance.

The effects obtained by the representative ones of the embodiments described above will be briefly described as follows.
(1) Data loss in the storage device can be prevented even if area degeneration occurs due to the occurrence of a defective erase block during writing.
(2) Further, it is possible to prevent a decrease in write performance in the storage device.
(3) It is ensured that a predetermined number of storage areas are always erased from the end in the data storage area.

  Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. Not too long.

    The embodiment disclosed in this specification is suitable for a data storage area management technique by a data management layer in a storage device such as a memory card.

It is a block diagram of the information processing system by Embodiment 1 of this invention. 3 is a flowchart illustrating an example of a new page securing process by the information processing system of FIG. 1. 3 is a flowchart illustrating an example of file deletion processing by the information processing system of FIG. 1. It is a block diagram which shows the structural example of the information processing system by Embodiment 2 of this invention. 5 is a flowchart illustrating an example of file deletion processing by the information processing system of FIG. 4. 6 is a flowchart illustrating an example of a used segment erasing process by the information processing system of FIG. 4. It is a flowchart which shows the metadata reconstruction process example of the file system area | region by the information processing system by Embodiment 3 of this invention. It is a flowchart which shows the metadata reconstruction process example of the segment by the information processing system by Embodiment 3 of this invention. The configuration diagram of the information processing system according to the first embodiment. FIG. 3 is a configuration diagram of an information processing system according to a second embodiment. It is explanatory drawing which showed the structure outline | summary of the online storage area management system which considered the generation | occurrence | production of the defect of the memory element which this inventor considered. It is explanatory drawing of the state transition in the non-volatile semiconductor memory which this inventor examined.

Explanation of symbols

4001 Main board 4002 Used page list 4003 Deleted page list 4004 General-purpose storage interface 4005 Memory card 4006 Memory controller 4007 Non-volatile semiconductor memory 4008 Used erase block list 4009 Used erase block list 4010 Deleted erase block list 4011 File system Area 4012 Used segment list 4013 Used segment list 4014 Erased segment list 2001 Wear leveling 2002 Reassign bad erase block

Claims (13)

A storage area management method for managing a storage device including a storage area group composed of a plurality of storage areas capable of storing data used by an application,
When the data stored in the first storage area is no longer used by the application, among the other areas of the storage area group, specify the last storage area in which the data used by the application is stored,
Move the data stored in the specified storage area to the first storage area, erase the data from the specified storage area,
Set the identified storage area as an erased storage area,
It is determined whether or not the number of erased storage areas including the set erased storage area is larger than a predetermined number of storage areas. Allocate storage from your erased storage to your application,
A storage area management method characterized by notifying that the application cannot be assigned if the size is small. In the storage area management method according to claim 1,
The management unit of the storage area is
A first management unit comprising a page as a minimum access unit in the storage device; a second management unit comprising a segment in which a plurality of pages are grouped; or the first management layer and the second management layer. A storage area management method, wherein the storage area management method is one of a third management unit hierarchized into a plurality of management layers. In the storage area management method according to claim 1,
A storage area management method, wherein an erase command corresponding to the storage apparatus is issued when erasing the contents of the used storage area. The storage area management method according to claim 1, wherein:
When erasing the contents of the used storage area,
A storage area management method, wherein erasure data is written to the used storage area. A storage area management method for managing data of a storage device by a logical data management layer having an exclusive control manager,
Obtaining write exclusive control rights for the entire data management layer from the exclusive control manager;
Acquiring a page management structure of the data management layer that acquired the exclusive control right;
Acquiring all the storage areas managed by the acquired page management structure, and listing what can be acquired from among them,
Determining the presence or absence of a storage area that cannot be acquired based on the listed list;
Reconstructing the page management structure based on the listed list when it is determined that there is an unacquirable storage area, and
When the data management layer is mounted at the first access to the data management layer, the storage capacity is changed in the data management layer when the storage capacity in the storage device is changed Management method. The storage area management method according to claim 5, wherein
The management unit of the storage area is
A first management unit comprising a page as a minimum access unit in the storage device; a second management unit comprising a segment in which a plurality of pages are grouped; or the first management layer and the second management layer. A storage area management method, wherein the storage area management method is one of a third management unit hierarchized into a plurality of management layers. A storage area management method for managing data of a storage device by a logical data management layer having an exclusive control manager,
Obtaining exclusive write control of the entire storage area from the exclusive control manager;
Obtaining a page management structure of the storage area from which the exclusive control right has been obtained;
Acquiring all storage areas managed by the acquired page management structure, and listing what can actually be acquired;
Determining whether there is an unacquireable storage area based on the listed list; and
Reconstructing a page management structure based on the listed list when it is determined that there is an unacquirable page; and
When the reconfigured page management structure does not include an available storage area, obtaining a write exclusive control right for the entire data management layer from the exclusive control manager; and
Obtaining a segment management structure of the data management layer that has acquired the exclusive control right;
Removing from the acquired segment management structure a segment that has acquired the write exclusive control right of the entire storage area from the exclusive control manager;
A storage area management method characterized in that, when it is detected that the capacity of the storage device has been changed, a change in storage capacity is processed in the data management layer. The storage area management method according to claim 7, wherein
The management unit of the storage area is
A first management unit comprising a page as a minimum access unit in the storage device; a second management unit comprising a segment in which a plurality of pages are grouped; or the first management layer and the second management layer. A storage area management method, wherein the storage area management method is one of a third management unit hierarchized into a plurality of management layers. An information processing apparatus,
An external interface to which a storage medium including a storage area group composed of a plurality of storage areas capable of storing data used by an application is connected;
A main board connected to an external interface,
The main board includes a processor on which the application is executed and a memory,
When the data stored in the first storage area is no longer used by the application, the processor stores the last storage area in which data used by the application is stored among other areas of the storage area group Identify
Move the data stored in the specified storage area to the first storage area, erase the data from the specified storage area,
Set the identified storage area as an erased storage area,
Determine whether the number of erased storage areas is greater than the predetermined number of storage areas. If the determination result is large, the storage area is deleted from the end of the erased storage area. Assigned to
An information processing apparatus characterized in that if it is small, an assignment impossible notification is sent to the application. An information processing apparatus according to claim 9,
The management unit of the storage area is
A first management unit comprising a page as a minimum access unit in the storage medium; a second management unit comprising a segment in which a plurality of pages are combined; or the first management layer and the second management layer. An information processing apparatus that is one of third management units hierarchized into a plurality of management layers. An information processing apparatus according to claim 9,
The information processing apparatus, wherein the processor issues an erasure command that can be recognized by the storage medium to the storage medium via the external interface when erasing the contents of the used storage area. The information processing apparatus according to claim 9.
When erasing the contents of the used storage area, the processor issues an instruction to write erasure data to the used storage area to the storage medium via the external interface. Information processing apparatus. An information processing apparatus according to claim 9,
The processor is
Acquire write exclusive control right to the storage area of the storage medium,
Acquire the page management structure of the data management layer that acquired the exclusive control right,
Acquire all the storage areas managed by the acquired page management structure, list what can be acquired from among them,
Based on the listed list, determine whether there is a storage area that cannot be obtained,
When it is determined that there is a storage area that cannot be obtained, the page management structure is reconfigured based on the listed list,
When the data management layer is mounted at the first access to the data management layer, the storage capacity is changed in the data management layer when the storage capacity in the storage medium is changed apparatus.

Images